Abstract

In this work, we present data on early lung development in term-born and preterm children from infancy to early childhood. We showed that our equipment for multiple-breath washout reliably measured lung volumes. Using both this newly validated and other established equipment, we were able to investigate several aspects of early lung development. Firstly, we investigated early lung growth in term-born children. Here, we observed a weak tracking of lung volume throughout young childhood, and no association of lung volume and function of larger airways. Secondly, we investigated early lung development in preterm children in infancy, at school age and over time. In infancy, we tested whether non-invasive lung function measurements could improve prediction of later respiratory symptoms when compared to established predictive tools, but found no improvement. However, we observed an altered breathing pattern in those preterm infants with later wheeze. At early school age, we investigated ventilation inhomogeneity in preterm children, and found differences in the peripheral lung regions compared to term-born controls. Investigation of lung volumes over time detected excessive pulmonary catch-up growth from infancy to early childhood in preterm children, and reduced physiological variability of breathing pattern. Children born prematurely showed higher relative lung volume increase when born at younger gestational age. In these observational studies, respiratory health and growth of peripheral lung structure beyond infancy did not seem to be determined by therapeutic inter- ventions, but by prematurity per se.